Myco-conversion of agricultural waste into new bioproducts to improve the biodiversity of agricultural ecosystem

Agriculture, while vital for sustaining a global population exceeding 8 billion, generates substantial agro-waste, posing ecological and economic challenges. Sustainable waste management strategies are urgently needed. This thesis explores myco-valorization—the use of fungi to convert agricultural waste into value-added products—as a circular, eco-friendly solution. Fungi natural decomposing abilities enable them to process complex organic materials while producing bioactive compounds. Advanced analytical techniques, such as Fourier Transform Infrared (FTIR) and Raman spectroscopy, support substrate characterization and process optimization. The research comprises four interconnected studies. Chapter 3 investigates integrating biogas production with mushroom cultivation by using anaerobic digestate as a substrate for Pleurotus ostreatus. Incorporating 15% digestate yielded comparable mushroom productivity and improved uniformity and timing of fruiting, supporting synergies between mushroom and biogas industries. Chapter 4 evaluates grape pomace, alone and mixed with digestate, as a cultivation substrate. Grape pomace enhanced yield and quality, with digestate optimizing pH and nutrients. The spectroscopic analyses confirmed the chemical consistency of mushrooms grown on these alternative media, highlighting grape pomace valorization potential. Chapters 6 focus on extracting chitosan from mushrooms and spent substrates to synthesize chitosan nanoparticles. FTIR, Surface-Enhanced Raman Scattering (SERS), and Dynamic Light Scattering (DLS) analyses revealed source-dependent variations in composition and particle characteristics. This demonstrates a viable route for producing high-value nanomaterials from fungal by-products. Chapter 7 utilizes SERS spectroscopy to study ergothioneine, a bioactive amino acid in fungi. Its molecular behavior under varying pH and concentrations was characterized, and in situ detection in fruiting bodies was demonstrated, positioning SERS as a valuable tool in fungal biotechnology. In conclusion, this thesis advances scalable strategies for agro-waste valorization through fungal applications, contributing to sustainable agriculture, biotechnology, and circular economy transitions. Future work should explore diverse substrates, fungal species, and innovative applications of fungal-derived products.